Method for cultivation of monarda fistulosa for production of thymoquinone

ABSTRACT

A method for cultivating  Monarda fistulosa  for production of thymoquinone includes planting seeds at rates between about 2.5 and about 5 pounds per acre, preferably about 4 pounds per acre. The heavy rate of planting produces plants bearing oil without weed contamination and reduces herbicide use due to production of natural herbicides by the  monarda  plants. Seeding and mowing the first season, and harvesting in seasons thereafter reduce costs. The method results in increased production of essential oils including thymoquinone and thymohydroquinone at levels up to about 40% or more of recovered oils, and which may be distilled from the plant.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation application of U.S. Ser. No. 14/286,543, filedMay 23, 2014, which is a continuation-in-part of U.S. Ser. No.13/804,026 filed Mar. 14, 2013 (now U.S. Pat. No. 9,073,824, issued Jul.7, 2015), and U.S. Ser. No. 13/359,045 filed Jan. 26, 2012 (now U.S.Pat. No. 9,029,610, issued May 12, 2015.

FIELD OF THE INVENTION

The present invention relates to a method for producing MonardaFistulosa for the efficient harvest of thymoquinone essential oil.

BACKGROUND OF THE INVENTION

Some plant essential oils have long been known to possess propertiesthat can be employed as food or flavoring, and for medicinal andindustrial purposes. Different plant species provide different oils. Forexample, peppermint for the peppermint plant's leaves which providesflavoring is sometimes used as an aid for digestive issues. And cloveoil is extracted from flowers and used for flavoring, scent, and varioushistorical medicinal purposes. Eucalyptus oil, produced from the leavesof Eucalyptus globulus is used in many cleaning solutions and as anantiseptic.

As another example, Monarda fistulosa and many other plants belonging tothe true mint family i.e. labiate, have been a source of geraniol,thymol and carvacrol essential oils. Geraniol is used in perfumes.Thymol is used in mouthwash as an antiseptic and has been shown to haveantifungal activity, as well. It is known that Carvacrol may also beused as an antimicrobial, antifungal and as a flavoring. Thymoquinoneand Thymohydroquinone are also essential oils present in the Monardafistulosa plant. Thymoquinone has recently been discovered to havespecific effects on some mammalian cancers and is a phytochemical foundin the plant Nigella sativa and several other plants. It is anantioxidant and has been shown to effect or decrease damage caused byheart, liver and kidney diseases in animal studies. Thymoquinone is anangiogenesis inhibitor and appears to have analgesic and anti-convulsanteffect. Tests have shown thyrnoquinone kills pancreatic cancer cells andmay have promise related to controlling certain kinds of epilepticseizures.

Although it would seem likely that every plant of a species would have asimilar oil content profile, it has been found instead that differentraces of a plant species may provide different ratios of the essentialoils they produce. There are many theories as to the reasons for thesedifferences which include response to climate, moisture levels, nutrientlevels, evolution due to these pressures, etc.

Many plants are indigenous to a particular geographic area and/orclimate. Historically, those who sought plant oils would gather manyplants from their natural habitat. Some plants containing desirable oilhave been cultivated for research purposes related to the oil. However,commercial use of Monarda to date includes propagation for seeds to addcolor to natural prairie and wildflower seed mixes, or selected SweetMonarda may be grown to produce geraniol used in perfumes.

Cultivation for research or seed purposes may include transfer of theplants from their native growth area to a different geography, climateor soil type or a combination of these. Natural travel of seeds from onearea to another may also result in new habitats for a given plantwherein the new habitat may include differing climate, soil, or pestsfrom those in the original habitat. It has been noted that such transfermay result not only in different physical characteristics of the plantin response to the environmental differences, but that these changesmay, in turn, result in different ratios of the oils produced by theplant.

Monarda is a genus consisting of at least about 16 species. The plantsare erect, herbaceous, annual or perennial, in the family Lamiaceae andare native to North America. The plants typically range in height from 1to 3 feet (0.2 to 0.9 m), the plants have an equal spread, with slenderand long-tapering (lanceolate) leaves. The leaves, when crushed, exude aspicy, highly fragrant oil. Common names include bee balm, horsemint,and bergamot, among others. When the term “Monarda” is used herein it isunderstood that it includes plants known by these names, as well,provided the plant meets the characteristics of the Monarda genus.

In the case of Monarda fistulosa, several studies provide informationpertinent to the present invention. In the early 1970's anew chemicalrace of Monarda fistulosa was discovered in Manitoba Canada and studied.(MARSHALL H, H, and R. W. SCORA.1972. A new chemical race of Monardafistulosa (Labiatae). Can. J. Bot. 50: 1845-1849.) Monarda fistulosa iswidely distributed throughout North America and a plant had beendiscovered having a different scent than most others. It was dubbed“sweet Monarda” due to the scent which was the only differencediscemable without chemical testing. Other Sweet Monarda plants werethen found, albeit far more scarce than the dominant type. The SweetMonarda plants were generally more scarce and did not grow at many ofthe study's collection sites. Typically, the sweet Monarda plants werecollected on light sand and stabilized dunes.

Sweet Monarda was crossed with other Monarda. Then the oils of thecrosses and of the Sweet Monarda were studied using chromatography ofthe leaf oil. The researchers found that oil from the nonsweet Monardawas moderately viscous and was reported clear and colorless whereas oilfrom Sweet Monarda smelled sweet. Chromatograms showed that oil from theSweet Monarda included far more geraniol but far less thymol andcarvacrol than the non-sweet Monarda plants tested.

Another study completed in 1993 looked at Monarda as a source of certainoils, specifically, geraniol, linalool, thymol and carvacrol. This studyalso presented the idea that plants of a given species but grown andmaintained in different geographical regions may yield different oils.(Mazza, G., F. A. Kiehn, and H. H. Marshall. 1993. Monarda: A source ofgeraniol, linalool, thymol and carvacrol-rich essential oils. p.628-631. In: J. Janick and J. E. Simon (eds.), New crops. Wiley, NewYork.)

When Monarda fistulosa is crossed with M. didyma a vigorous hybrid isproduced that yields geraniol, linalool, thymol, carvacrol and otherterpenes. However, multiple crosses as conducted by the study resultedin a sterile plant which had to be propagated by division. The studyemployed a planting rate of 10,000 plants/ha (or 24,000/acre). The studyacknowledged that propagation via crown divisions would be easilyachieved but, because crown division is cumbersome and inefficient, thestudy recommended using stem cuttings instead. The cuttings wererecommended to be 10-12 cm in length with their bases dipped in rootingcompound and then placed in sand in a misting chamber. Roots werereportedly produced in a week using this method and recommended to betransplanted in 14-16 days. Further, weeds were reported as being easilycontrolled by herbicides such as trifluralin, terbaacil, solan, andparaquat. Post-harvest, hydrodistillation was employed to extract theoils which were then subjected to gas chromatography and massspectrometry. One of the hybrids showed a high level of geraniol; thishybrid was grown for a short time in southern Alberta, Canada forgeraniol production but for an unknown reason, the plants did notsurvive the second year.

Rust, otherwise known as Puccinia menthe, was reported as the majordisease of the sterile Monarda (Mazza, 1993) causing defoliation, stemdamage and degeneration of plants. Recommendations for control of rustinclude application of the herbicide paraquat in early spring. Thisarticle also reported variations of essential oil yields between about0.65 and 1.2 g/100 g of fresh plant material or between about 60-125 kgof oil/ha.

As described earlier, Carvacrol and Thymol have both antiseptic andantimicrobial activities and have been used accordingly. It also appearsthat one or both may be used as an herbicide of sorts, specifically, abiochemical fungicide for control of moss and liverwort. Geraniol isused most often for its scent in products such as perfumes.Thymoquinone, as mentioned earlier, is indicated as having therapeuticeffect in the treatment of some mammalian cancers and other ailments.

In the present invention, it was postulated by the inventors that levelsof oil, and perhaps quality of the oil, in the Monarda fistulosa plantsmay be at least somewhat dependent on planting and growth methods.Finding a dependable means of growing and harvesting oil from Monardafistulosa in a manner selective for the desired oil would be beneficial.Developing a method that minimized use of herbicides and pesticides wasalso desirable in order to produce high quality oil unadulterated bychemical use.

For the most part, historically Monarda fistulosa has been cultivated asa seed for wildflower planting purposes rather than for oil productionalbeit some plants have been selected for geraniol production

Monarda fistulosa is an erect aromatic annual or perennial plant whichbears pretty pinkish/lavender flowers. It is often used in wildflowerseed mixes and in prairie restoration projects. Previously recommendedmethods for cultivation of Monarda fistulosa include planting rates ofbetween about 0.25 lbs/acre and 2 lbs/acre, and cutting and or splittingthe plants to increase them, timing of harvest, etc. In terms of laborand time costs, the previous methods are not ideal. Further, none of theliterature purports to claim these methods increase the average levelsof certain components in the oil such as thymol, carvacrol orthymoquinone.

What was needed was a method of producing Monarda fistulosa on acommercial scale and economically to produce an oil comprisingrelatively high levels of carvacrol, and/or thymoquinone and/orthymohydroquinone. A desirable method of doing so would reducecultivation expenses and labor while providing a dependable means for areliable harvest of the multi-use oil and its constituents.

It was therefore one objective of the present invention to determineappropriate seed planting rates and spacing to provide and encourageefficient production of plants bearing oil having higher levels ofcarvacrol and/or thymoquinone and/or thymohydroquinone.

It was another objective of the present invention to provide a method ofgrowing Monarda fistulosa that would result in least expense for weedand/or rust control while providing high levels of desired essential oilor oils.

It was another objective of the present invention to provide a methodfor cultivating Monarda fistulosa that reduced the amount of fuelrequired, specifically by reducing the need for fuel used to applyherbicides, and boiler fuel used in distilling/cooking through unwantedweeds mixed in with the Monarda.

It was another objective of the present invention to provide a methodfor planting, cultivating and harvesting Monarda fistulosa that providedan economically viable manner of producing one or more essential oils.

It was a primary objective of the present invention to provide a methodof cultivation of Monarda fistulosa that increased consistent results ofhigh quality and relatively high production levels of the desired oilconstituents.

SUMMARY OF THE INVENTION

The present invention includes a recommended planting rate andcultivation methodology that has heretofore been unknown. The methodincreases germination, decreases herbicide use and fuel use, increasesthe yield of Monarda fistulosa oil, and increases the yield of certainessential oils such as carvacrol, thymoquinone, and thymohydroquinone,alone or in various combinations of increasing yields of these oils.

Although known recommended planting rates for Monarda fistulosa rangedfrom about 0.25 to up to 2 lbs per acre (Monarda fistulosa contains1,120,000 seeds/lb) for producing seeds for use in wildflower seed mixesand prairie grasses, it was surprisingly found that these rates did notprovide the better means for cultivating and harvesting the plants andthe desired essential oils they contained. At the rates previouslyrecommended, weed pressure causes a decrease in yield of oil, and causesan increase in levels of unwanted contaminants associated with thoseweeds (e.g. aromatic sap from the weeds) which may appear in theharvested oil, decreasing its quality. These contaminants may reduce oilquality by up to 40%. Removing these weeds from a field of Monardafistulosa to avoid the contamination and downward pressure on yieldrequires more fuel to be used in the operation to remove/destroy thoseweeds and/or requires herbicides which, in tum, may negatively impactoil yield and quality. The result is a reduction in the efficiency ofthe overall operation.

The inventors experimented in a 12-acre field, drill seeded at differingrates. Specifically, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5 and 5.0 pounds of seedper acre. Photos taken 5 days prior to harvest showed a dramaticdecrease in weeds at the higher rates versus those in the lower plantingrates at the first harvest. Photos taken 30 days after harvest showedthat the lower planting rates of Monarda fistulosa planting resulted inhigher weed pressure even at this stage which, in tum, will translate toincreased pressure the following season.

Further, it was determined that rolling the ground after either drillingor broadcast seeding increases germination, or use of a cultipacker topack the soil even tighter may provide even higher levels ofgermination. Theoretically, the soil compression provided by the rolleror cultipacker provides a better barrier for retaining moisture and forprotection against birds or other pests while the seeds germinate.

In contrast to prior methods, the present invention recommends plantingrates ranging from about 2.5 lbs/acre to about 5 lbs/acre or, morepreferably, around about 4 lbs/acre either via broadcast seeding ordrilling. This is about twice the planting rate that has previously beenrecommended for growing Monarda fistulosa. Further, the method includesrolling the ground securing the soil around drilled or broadcast seedsto seal in moisture and protect the seeds. Alternatively, Monarda may beplug planted, but the population density must be at least comparable tothat expected to result from the planting rates herein recommended.Specifically, plug planting at a rate between about 45,000 and about60,000 plugs per acre is recommended.

In some embodiments, the method advises no harvest the first season but,rather, regular mowing. Some embodiments provide recommended methods ofweed control that are plant-population dependent, others employherbicides or some combination of the two. Recommendations regardingpesticide use and fertilizer application are also provided.

The new method advocates certain practices related to harvesting Monardafistulosa for best yield of the desired oil and increase in certainconstituents of that oil. The method also describes means and methodsfor separating the oil from the plant. Finally; the method includesrecommended best practices for the maintenance of the perennial andnumber of seasons for production prior to destruction.

In short, one of the preferred embodiments includes drilling seed orbroadcast seed application of between about 2.5 lbs and about 5 lbs peracre, more preferably between about 3.5 lbs and about 4.5 lbs per acre,and most preferably around 4 lbs per acre. Once seeded, means to sealmoisture in and around the seed are employed. A recommended method isthe use of a roller across the field to both compact the soil to adegree and to seal in moisture. Alternatively, or in addition, acultipacker may be employed. Seeding is done in the spring of the year.

Alternatively, seedlings may be nursery grown and transplanted as plugs.It is important that regardless of whether seeding or plug planting, theplant density is about the same. Recommended rates for plug planting arebetween about 45,000 and about 60,000 per acre. Monarda fistulosa andother Monarda types may all benefit from this cultivation method.Further, the maturity of the plant may influence its essential oilprofile. Specifically, this invention may be used to grow, harvest andobtain oil from at least those listed in Table 1.

TABLE 1 Monarda Didyma L. Monarda Media Willd Monard Menthifolia GrahamMonarda bradburiana Beck Monarda fistulosa Sims, nom. inq. Monardarigida Raf. Monarda villosa M. Martens Monarda media Willd. Monarda ×medioides Duncan [fistulosa × media] Monarda dressleri Scora [excluded]Monarda fistulosa L. Monarda fistulosa L. ssp. Fistulosa Monardafistulosa L. ssp. fistulosa var. fistulosa Monarda fistulosa L. ssp.fistulosa var. menthifolia (Graham) Fernald Monarda fistulosa L. ssp.fistulosa var. mollis (L.) Benth. Monarda mollis L. Monarda scabra BeckMonarda fistulosa L. ssp. fistulosa var. rubra A. Gray Monarda fistulosaL. var. brevis Fosberg & Artz Monarda fistulosa L. ssp. brevis (Fosberg& Artz) Scora, ined.

Other objects, features, and advantages of the present invention will bereadily appreciated from the following description. The descriptionmakes reference to the accompanying drawings, which are provided forillustration of the preferred embodiment.

However, such embodiment does not represent the full scope of theinvention. The subject matter which the inventor does regard as hisinvention is particularly pointed out and distinctly claimed in theclaims at the conclusion of this specification. The invention has beendisclosed in such a way as to enable one of ordinary skill in the art topractice the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 flow chart describing the cultivation process;

FIG. 2 perspective view of means for transporting;

FIG. 3 end view of means for transporting; and

FIG. 4 schematic illustrating steam distillation components.

FIG. 5 chart showing levels of constituents in the oil harvested fromplants grown according to the described cultivation process.

DETAILED DESCRIPTION OF THE INVENTION

The present invention comprises planting seed of Monarda fistulosa orany of the species listed in Table 1 in a field at a rate between about2.5 lbs per acre and about 5 lbs per acre and more preferably betweenabout 3.5 and 4.5 lbs per acre. Alternatively, plants 14 may be plugplanted at a rate between about 45,000 and about 60,000 per acre. Thefield 12 should be mowed regularly the first year without harvesting theplant or its heads/blooms, and then harvesting it in years thereafter.Harvest may include stems (generally the section above the groundlevel), along with leaves and heads, or may be more limited toharvesting just heads without stems and leaves. The lifetime of plants14 for a single planting is typically 5-7 harvests, but may be longer orshorter depending on soil conditions, climate and husbandry practices.The equipment used to condition the field, plant the seed (where seedingis employed rather than plug planting), or, alternatively, plant theplugs, mow the plants, cut the plants, and gather the heads and leavesor whole plants may each be of any type readily known and understood byone of skill in the art. Examples of each of these types of equipmentare provided herein by machine producer's brand name but they areprovided strictly for purposes of example, and not for limitation.

Referring now to FIG. 1 the field 12 is prepared 2 by routine tilling,field cultivating, discing or other means for turning or loosening theupper layer of soil. For example and not for limitation, a disc 16 byCaseiH, Krause, or other implement dealer may be used. Depending on soiltype, fertilizer may or may not be applied. Next, the field is seeded 4.Seed 10 may be drilled or broadcast. When drilled, spacing of about 8inches to about 10 inches is desired. Although many permissible drillsexist, two examples are produced by Brillion or Taka. Alternatively, theseed 10 may be broadcast. Again, a variety of acceptable broadcastingdevices are available such as a TerraGator. In either case, broadcastingor drilling, seed 10 should be planted at the rates mentioned above.

Alternatively, plants may be plug planted at generally even spacing forabout 45,000 to about 60,000 plugs per acre. The plugs may be planted inrows or groups or generally equidistant.

In a preferred method, planting (via drill or broadcast or other means)is preferably followed by rolling or other soil compression activities6. An example of an acceptable roller device is a Riteway model 4300which weighs between 15,800 lbs and 23,500 lbs. Rolling or othercompression actions are preferably completed the same day as the fieldis cultivated and also, and more critically, within 2 to 48 hours afterdrilling or broadcasting seed. The timing is recommended in order toavoid overdrying the soil, protect the seeds from birds, and to compressthe soil enough to create a seal to assist in retaining the remainingmoisture to improve germination percentages for the seeds.

In another method, the soil may be prepared to minimize clods andprovide soil texture amenable to plug planting. Thereafter, plugs may beplanted, and then lightly rolled to seal the ground, or if row planted,soil may be tamped between rows. However, a sealing process is notcritical for the transplanted plants.

During the first season (whether seeded or plug planted), the field 12should be mowed 8 on a regular basis. Depending on rainfall, soil andclimate conditions, mowing may be done as often as 4-6 times in a seasonor as infrequently as 2-4 times. Mowing frequency is dictated by theheight of the plants. Weeds grow much faster in the first season thandoes the Monarda, so mowing is aimed to keep the weed height reduced toallow the Monarda to become established. Mowing should be done tomaintain the field between about 8 and 10 inches and, more preferablywhen they are about 8 inches tall, as many times in the first season asneeded to keep the plants less than about 8 to 10 inches high. At theend of the first growing season, the plants are preferably left around 8inches tall to catch snowfall. Any suitable mowing machine 24 may beemployed. For example, several models of the Woods bat-wing mower workwell.

It is foreseeable that seeds 10 planted in a bare field 12 the firstseason where ground cover or crop previously existed may be subjected tosome weed pressure early in the growing season of that first year. Whenthis occurs, application of Assure II or Select Max work well. Otherherbicides applications 10 are also likely to be effective, however,broadleaf herbicides should not be used because they damage Monarda.

The second growing season is unlikely to require any herbicides,however, Assure II, Basagran and SelectMax are but a few examples ofherbicides that may be employed if needed. Due to the planting rate, thecompression of the soil, and multiple mowings in the first season,plants will emerge early and tend to grow quickly. Monarda fistulosaplants 14 produce their own herbicidal chemicals one of which iscarvacrol. These chemicals act to control any weeds that are not simplyphysically crowded out by the Monarda. The action of the carvacroleffects germination of the weed seeds. The planting rate, the growthrate, the size of the plants, and the Monarda's own chemical defensesresult in a crop that typically requires no further herbicide treatmentsbut for, perhaps, an occasional weed patch which may be controlled viahand sprayer or physical removal.

In midsummer, Monarda fistulosa plants produce a lavender coloredfragrant flower. The plants are harvested at flower peak which, in theMidwest United States, is generally early to mid-July. The flowerscontain the essential oil as do the stems and the leaves.

Harvest of Monarda fistulosa fields cultivated in the manner of thepresent invention may be accomplished in several ways using variousequipment. A preferred method is to employ a MacDon draper or any othercutting machine to cut 12 the plants 14 with flowers attached and leavethem lay where they were cut. The cut plants may remain in the field forup to about 12-to about 24 hours but oil can also be reasonablyharvested if the plants are left as little as 2-6 hours or 4-6 hours 16.It is best, but not critical, that these hours be warm and sunny.Leaving the plants lay starts the process of oil release from theinter-cellular pockets within the plant. The cut plants 14 are thengathered by a suitable device such as a forage chopper 18 and placed inmeans to transport 30 them from the field.

Alternatively, the plants (alternatively, the flower heads only, or theflowers and leaves only) may be harvested freshcut and transporteddirectly to the still. It is theorized that senescence of the flowerheads caused by the harvest process results in release of oil and mayalso influence the constituents of the distilled oil. Specifically,flower senescense is the terminal phase of developmental processes thatlead to the flower's death. Those processes include wilting, shedding offlower parts, and fading. The flowers' senescence is much faster thanthat of other plant parts and certain stimuli may upregulate certaincatabolic processes. Those processes may cause the breakdown andremobilization of different cellular constituents. Further, theresources in the flower may be transported within the plant to meetother needs in an ultimate recycling and conservation of resourcessystem. It is theorized that the constituents of the harvested oildiffer relative to post-harvest time lapse and, therefore, distillationof flower heads at a freshcut stage may result in oil having differentprofiles.

In one embodiment, means to transport 30 the cut plants 14 comprises agenerally watertight wagon having a floor 32, two sides 34, 36, and twoends 38 and 40 with multiple ports 41-45 near the floor 32 in one of theends 38 or 40. The wagon 30 just described is used in one of severalmethods for removing oil from Monarda fistulosa, specifically steamdistillation.

Steam distillation of oil from plants is old in the art and works on theprinciple that steaming the cut plants encourages release of the plants'essential oils via rupture of the plant's oil sacs which are taken upwith the steam. During steam distillation 20 a boiler 48 creates steam50. The steam 50 travels through a conduit 51 to said means to transport30 (or some other container wherein said plant parts are present) andenters through ports 41-45 near the floor 32. The steam travels upwardmoving oil 52 that has been released upward with the steam 50. The steam30, with oil 52, is removed through the port 56 into a second conduit58. The steam 50 and oil 52 is run through a condenser 54 which causesthe oil 52 and water in the steam 50 to condense and allows the oil 52to be separated and recovered 22. When using the wagon 30, a steam input61 is connected to each port 41-45. Steam is injected into the wagonand, as it travels upwards, oil 52 from the plants 14 is removed withthe steam. The steam and oil then exit the top of the wagon through theport 56 and flow into or through one of many different kinds ofcondensers 60 where the oil 52 is recovered and the condensed steam(water) may or may not be reheated and reused in the process.

During distillation, the essential oils are separated from thedistillate in an order characteristic of the oil and related to theboiling point of that oil. (See Table 1 below) Thymoquinone separatesjust before thymol and carvacrol and thymohydroquinone separates justafter carvacrol.

TABLE 2 compounds molecular weight boiling points alpha pinene 136.24155 alpha thujene 136 155 alpha terpinene 136.237 164 beta myrcene136.23404 167 para cymene 134.22158 179 gamma terpinene 136.23404 182linalool 154.252 198 terpinene-4-ol 154.249 212 thymoquinone 164.204 231thymol 149.66 232 carvacrol 150.221 238 caryophyllene 204.356 256thymohydroquinone 166.217 306

The method of cultivation just described increases germination,decreases herbicide use and fuel use, and increases the yield of Monardafistulosa oil generally, and specifically, effects relative amounts ofcarvacrol, thymol, and thymoquinone (TQ) and thymohydroquinone (THQ).Oil yield from various methods of cultivation are presented on Table 1.At least after the first year's growth, and more commonly also after thefirst year including harvest, the TQ and THQ levels, together, mayconstitute about 25% to 35% and up to about 50% of the oil distilled andeither carvacrol or thymol constitute over 20% of the oil distilled, ortogether constitute over 20% of the oil distilled.

The above-mentioned cultivation method results in oil content that iscommercially desirable, namely, containing increased amounts ofcarvacrol, thymol, thymoquinone, and thymohydroquinone. Although knownrecommended planting rates for Monarda fistulosa ranged from about 0.25to up to 2 lbs per acre (Monarda fistulosa contains 1,120,000 seeds/lb),it was surprisingly found that these rates did not provide the bettermeans for cultivating and harvesting the plants and obtaining thedesired essential oils they contained at the level of oil quality andprofile desired. Oil quality of the present invention is high at leastpartially due to the reduction and near elimination of weed pressure andits resulting contamination. The quality may also be partiallyattributed to low uses of herbicides or pesticides. The oil constituentprofile is also beneficially effected by control of weed pressure underless chemical pressure and the cultivation practices described herein.It is believed also that harvesting methodology at least relative totime between harvest and distillation, and perhaps also relative toplant parts, also attributes to oil profile.

Thus, the present invention has been described in an illustrativemanner. It is to be understood that the terminology that has been usedis intended to be in the nature of words of description rather than oflimitation.

Many modifications and variations of the present invention are possiblein light of the above teachings. For example, distillation may beaccomplished in other ways; seeds may be planted via hand, or viatraditional planters, or other seed planting devices not yet known. Neweffective herbicides may become known. New Monarda hybrids may bedeveloped and it may be determined that other mans may be employed toincrease oil production even more, specifically the level of carvacrolor of thymoquinone or thymohydroquinone in the Monarda. Therefore,within the scope of the appended claims, the present invention may bepracticed otherwise than as specifically described.

What is claimed is:
 1. A method for cultivating plants of at least onespecies of Monarda selected from a group consisting of the speciesfistulosa and dydima, to increase yield of at least one constituent ofessential oil of said plants, said at least one constituent from thegroup consisting of thymoquinone and thymohydroquinone, said methodcomprising preparing a field for planting Monarda fistulosa, growing atleast about 60,000 Monarda plants per acre, and harvesting plants grownin said field.
 2. The method of claim 1 further comprising planting seedof Monarda fistulosa with a broadcast seeding device at a rate ofbetween about 2.5 pounds and about 5 pounds per acre.
 3. The method ofclaim 2 further comprising using a soil compression device after seedingfor at least partially sealing in moisture.
 4. The method of claim 1further comprising planting plug plants of Monarda fistulosa at a ratebetween about 45,000 and about 60000 plugs per acre.
 5. The method ofclaim 1 further comprising a plurality of seasons wherein said plantsare mowed at least once without harvesting during a first growingseason, and harvested after each of the remaining plurality of growingseasons.
 6. The method of claim 1 wherein the yield of thymoquinone andthymohydroquinone together comprise at least about 30% of the oil yield.7. The method of claim 1 wherein the oil yielded further comprises lessthan about 5% thymol.
 8. The method of claim 1 wherein the oil yieldedcomprises at least about 30% thymoquinone and thymohydroquinone combinedand at least about 20% carvacrol.
 9. The method of claim 1 wherein theoil yielded comprises about 38% to about 42% thymoquinone andthymohydroquinone and less than about 10% of one of carvacrol or thymol.10. The method of claim 1 wherein harvesting plants comprises cuttingthe plants, allowing the plants to lay in the field for a plurality ofhours, gathering the plants, and separating said oil from said plants bysteam distillation.
 11. The method of claim 1 wherein at least onequality of said at least one essential oil is improved over methodswhere planting rates of seed are less, said at least one qualitycomprising levels of contamination of the oil caused by the presence ofother plants.
 12. The method of claim 10 wherein said plurality of hourscomprises a range between about 12 hours and about 24 hours.
 13. Themethod of claim 10 wherein said plurality of hours comprises a rangebetween about 2 hours and about 6 hours.
 14. The method of claim 1further comprising separating said at least one constituent from the oilusing a process comprising distillation.
 15. The method of claim 14wherein separating said at least one constituent yields an amount ofthymoquinone of at least about 30% of the oil.
 16. The method of claim15 said at least one constituent further comprising carvacrol whereinseparating said at least one constituent further yields an amount ofcarvacrol of at least about 20% of the oil.
 17. A plant comprising oil,said oil including thymoquinone, carvacrol, and thymol wherein saidthymoquinone comprises at least about 30% of said oil and said carvacrolcomprises at least about 20% of said oil.
 18. A plant produced by themethod of claim 11, said plant comprising between about 34% and about37% thymoquinone and between about 20% and about 27% carvacrol.
 19. Amethod of harvesting said plurality of plants produced in a field by themethod of claim 1 comprising cutting said plurality of plants, gatheringsaid plurality of plants, and distilling oil from the plurality ofplants.
 20. The method of claim 19 wherein at least some of saidplurality of plants each comprise a flower head, said method comprisingseparating a plurality of flower heads from said at least some of theplurality of plants, gathering the plurality of flower heads, anddistilling oil from said flower heads.
 21. The method of claim 19further comprising leaving the plurality of plants lay in the field frombetween about 2 to about 24 hours prior to gathering said plants. 22.The method of claim 20 wherein at least some of said plurality of plantsfurther comprise leaves, said method further comprising separating saidleaves from said plant and distilling oil from said leaves.
 23. Themethod of claim 22 said method further comprising distilling oil fromthe leaves and flower heads together.
 24. The method of claim 19 saidmethod comprising minimizing delay between separation of said flowerheads, gathering said flower heads, and distilling oil.